POGO vibration is a low-frequency vibration problem which can not be ignored in the course of liquid rocket flight, it belongs to fluid-solid coupling dynamics.
POGO振動(dòng)是大型液體火箭飛行過程中遇到的一個(gè)不容忽視的低頻振動(dòng)問題,屬于流固耦合動(dòng)力學(xué)研究范疇。
The acceleration response of the vibration reaches maximum when the POGO vibration happens,and the phase difference between the pulsatory thrust force and the acceleration response is equal to-π/2.
分析結(jié)果表明,臨界阻尼比的增大會(huì)導(dǎo)致火箭結(jié)構(gòu)系統(tǒng)失穩(wěn),而增大蓄壓器氣蝕柔度可降低臨界阻尼比,提高系統(tǒng)穩(wěn)定性;產(chǎn)生POGO振動(dòng)時(shí),結(jié)構(gòu)振動(dòng)的加速度響應(yīng)最大,且推力脈動(dòng)與加速度響應(yīng)的相位差為-π/2;蓄壓器在推進(jìn)系統(tǒng)上的安裝位置對(duì)POGO抑制有重要影響,給出了蓄壓器安裝的最佳位置。
For the purpose of fast and effective elementary analysis of POGO vibration problem which possibly appear in the liquid launch vehicle engine,the study on calculation of natural frequency for engine flow system, with general applicability to any liquid launch vehicle engine, is proposed.
為了能夠快速有效地對(duì)各種構(gòu)型的液體運(yùn)載火箭可能出現(xiàn)的POGO振動(dòng)問題進(jìn)行初步分析,對(duì)液體運(yùn)載火箭推進(jìn)系統(tǒng)固有頻率的通用化計(jì)算問題進(jìn)行了研究。
Through analyzing the theory of posture alignment,the cumulative properties of the posture and the stress state of 3-axis POGO sticks are revealed.
針對(duì)飛機(jī)數(shù)字化裝配中大部件調(diào)姿與對(duì)接問題,設(shè)計(jì)了一種精密三坐標(biāo)POGO柱,在此基礎(chǔ)之上提出了一種基于三坐標(biāo)POGO柱三點(diǎn)支撐的姿態(tài)調(diào)整方法。
A control study of magnetic resonance diffusion weighted imaging of patients with acute cerebral infarction and early(<48 hours) intervention with resuscitating and scalp acupuncture therapies(醒腦開竅針刺加頭針法);
醒腦開竅針刺加頭針早期介入治療腦梗死的磁共振彌散加權(quán)成像對(duì)照研究
A Clinical Judgment of SCL-90 on Treating 50 cases of Depression with Scalp Acupuncture;
頭針治療抑郁發(fā)作SCL-90評(píng)定結(jié)果分析
Scalp Acupuncture for Treatment of Apoplexy and Effect on Plasma ET Content;
頭針治療中風(fēng)及對(duì)血漿內(nèi)皮素含量的影響
Significance of Nerve Stem Cells in the Research on Clinical Treatment of Ischemic Stroke with Scalp-acupuncture Therapy;
神經(jīng)干細(xì)胞在頭針治療缺血性腦卒中研究中的意義
Scalp-acupuncture on Cell Apoptosis in Acute Cerebral Ischemia Reperfusion Injury Rats;
頭針對(duì)急性腦缺血再灌注大鼠細(xì)胞凋亡的影響
Effects of Scalp-acupuncture on Expression of Bcl-2/Bax in Acute Cerebral Ischemia/Reperfusion Injury Rats;
頭針對(duì)急性腦缺血再灌注大鼠Bcl-2/Bax表達(dá)的影響
Design and accuracy for POGO stick with three-axis
一種精密三坐標(biāo)POGO柱設(shè)計(jì)與精度研究
Structure Design of POGO Stick with 3-DOF and Analysis of Its Mechanical & Dynamic Characteristics;
三坐標(biāo)POGO柱的結(jié)構(gòu)設(shè)計(jì)及其力學(xué)特性、動(dòng)態(tài)特性分析
Posture Alignment for Large Aircraft Parts Based on Three POGO Sticks Distributed Support
基于POGO柱三點(diǎn)支撐的飛機(jī)大部件調(diào)姿方法
3-D Column Chart Button\\015\\015Creates a column chart with 3-D markers.
創(chuàng)建具有三維坐標(biāo)刻度的柱形圖。
Discussion on the Calculation of Threefold Integral in a Cylindrical Coordinate System
在柱坐標(biāo)系下三重積分計(jì)算法的探討
A practical algorthm of cylindricity evaluation on the three CMMs
三坐標(biāo)測(cè)量機(jī)上圓柱度評(píng)定的一個(gè)實(shí)用算法
The Application of PML in Three Dimension Cylindrical Coordinates and the Conversion from Near Field to Far Field;
PML在三維柱坐標(biāo)系下的應(yīng)用及近場-遠(yuǎn)場轉(zhuǎn)換
Numerical Simulation of Eletromagnetic Propagation Logging by FDTD in 3-D Cylindrical Coordinates
三維圓柱坐標(biāo)系下FDTD法對(duì)電磁波傳播測(cè)井的數(shù)值模擬
Laplacian in the Columnar and Spherical Coordinates;
柱面坐標(biāo)系和球面坐標(biāo)系中的拉普拉斯算符
This coordinate system is called the triad at the point.
這個(gè)坐標(biāo)系叫做該點(diǎn)的三面形坐標(biāo)系。
Research on the Virtual Coordinate Measuring System of Coordinate Measuring Machines;
三坐標(biāo)測(cè)量機(jī)虛擬坐標(biāo)測(cè)量系統(tǒng)研究
Evaluation Algorithm of Cylindricity Error Based on Coordinate Transformation
基于坐標(biāo)變換的圓柱度誤差評(píng)定算法
Traditional coordinate measuring machines (CMMs) with Cartesian coordinate system, columniation coordinate system and other coordinate systems are widely used.
傳統(tǒng)的坐標(biāo)測(cè)量機(jī)大都基于一種幾何坐標(biāo)系,如笛卡兒坐標(biāo)系,柱坐標(biāo)系等。
A 3-D perspective column chart compares data points along two axes, showing variation over a period of time or illustrates comparisons among items.
三維柱形圖沿兩個(gè)坐標(biāo)軸比較數(shù)據(jù)點(diǎn)，顯示一段時(shí)間內(nèi)的變化或圖示項(xiàng)目之間的比較情況。
three-dimensional search and height finding radar
三坐標(biāo)搜索與測(cè)高雷達(dá)
The third coordinate is elevation.
第三項(xiàng)坐標(biāo)是高程。
Method of 2D and 3D Radar Registration and Its Application
兩坐標(biāo)與三坐標(biāo)雷達(dá)配準(zhǔn)方法及其應(yīng)用分析
Transformation Between Three-Dimension Geocentric Coordinate System and Independent Coordinate System
區(qū)域性獨(dú)立坐標(biāo)系與三維地心坐標(biāo)系的轉(zhuǎn)換